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Magnetic properties of double perovskites Ca2LnRuO6 (Ln = Y, La–Lu) were investigated. From the magnetic susceptibility and specific heat measurements, it is found that all the title compounds show an antiferromagnetic transition (TN = 10–34 K), and that the antiferromagnetic ordering of Ru5+ ions with a doublet ground state occurs below these temperatures. In these compounds, the larger Ln ions tend to occupy the A site of the perovskite ABO3, while the smaller Ln ions tend to occupy the B site. The Nd ions in Ca2NdRuO6 are situated at the A site and show an antiferromagnetic transition at 1.6 K, which is much lower than TN = 11.5 K. On the other hand, the Yb ions in Ca2YbRuO6 are situated at the B site, and a long-range antiferromagnetic ordering due to both Yb3+ and Ru5+ ions occurs at 34 K. The magnetic structure of Ca2YbRuO6 was determined by powder neutron diffraction measurements; it shows a non-collinear arrangement between Yb3+ (∼1.3 µB) and Ru5+ (∼1.7 µB) moments.

We discovered superconductivity in the ternary antimonide La 6 ZnSb 15 , and its superconducting properties were discussed through the resistivity, specific heat, and magnetization measurements. The crystal structure of La 6 ZnSb 15 is the orthorhombic La 6 MnSb 15 -type structure consisting of Sb sheets. Its electronic structure indicates that the conduction bands are mainly originated from Sb 5p orbitals in these Sb sheets. The electrical resistivity and magnetization measurements reveal that this compound is a type-II superconductor below 3.7 K. The upper critical field at zero temperature, µ 0 H c2 (0), is determined to be 851(8) mT. In the normal state, the electronic specific heat coefficient, γ, and the Debye temperature, Θ D , are found to be 18.8(8) mJ/mol K 2 and 218(1) K, respectively. From the electronic specific heat in the superconducting state, this compound belongs to a typical weak-coupling BCS superconductor.2